Research on Virtual Synchronous Machine Control of Air Conditioner Loads Participating in Power Frequency Regulation

High penetration of renewable energy reduces power-system inertia and increases the need for fast-frequency-support resources. This study proposes an integrated virtual synchronous machine (VSM) control framework for clusters of variable-frequency air conditioners (VFACs). The proposed method incorporates synchronous-machine-like inertia and damping into compressor-side power control, aggregates heterogeneous VFACs using fuzzy C-means clustering, and adaptively adjusts virtual inertia according to grid-frequency variations. Virtual-storage flexibility is further incorporated into coordinated frequency regulation. Simulations on the IEEE two-machine, five-node system verify the effectiveness of the proposed framework. Under a representative 3 MW load-increase disturbance, the frequency deviation from the nominal value is reduced from 0.11 Hz to 0.04 Hz. The results indicate that large-scale VFAC clusters can provide fast and coordinated demand-side frequency support while improving system frequency stability.